The objective of this study was to verify the effects of the various stages of seed processing on physiological seed quality. Flattened seeds of two corn hybrids were collected with a 22 L sieve on reception and subjected to seven processing stages, including drying, pre-cleaning, cleaning, separation by thickness and the gravity table. The control treatment involved only harvesting and manual threshing. The following tests were done: standard germination, seed purity, first count, velocity germination index, accelerated ageing, seed viability (tetrazolium), cold test, radical length, hypocotyl length, seedling dry matter, soil emergence and controlled deterioration. The experimental design was entirely randomized with four repetitions. Seed processing improved seed quality and those seeds obtained after passing through the gravity table and those ready for bagging showed the best physiological quality.